Thirty-nine years after his first mouthful, a retired prison guard has secured his place in the pantheon of food eating feats by finishing his 25,000th Big Mac.

Don Gorske, who nibbles his way through each burger in 16 bites, was honoured for passing the milestone at a McDonald's in his hometown of Fond du Lac, Wisconsin.

"I plan on eating Big Macs until I die," said the 57-year-old. "I have no intention of changing. It's still my favourite food. Nothing has changed in 39 years. I look forward to it every day."

Gorske's obsession with the burger – two all-beef patties, sauce, lettuce, cheese, pickles and onions on a sesame seed bun – started on 17 May 1972 when he bought three Big Macs to celebrate the purchase of a new car. He says he was immediately smitten and went back to McDonald's twice the same day, eating nine before the restaurant closed.

In 2004, his appetite for fast food prompted him to appear in the Morgan Spurlock documentary Super Size Me and he says he has only gone eight days without a Big Mac since his first bite, once to grant his mother's dying wish.

Despite his obsession Gorske says he has been given a clean bill of health by his doctor and takes regular exercise.

However, he did admit to an obsessive compulsive personality, adding he liked to collect the packaging and enjoyed counting his Big Mac intake because of a love of numbers.

He has also kept many of the Big Mac receipts over the years, and has noted his purchases in calendars he has kept.

McDonald's says there are 540 calories in a Big Mac, which is more than a quarter of the calories a person on an average 2,000-calorie diet would consume. The burger also contains 29g of fat and 1,040mg of sodium, which are both more than 40% of the Food and Drug Administration's daily recommended value for a 2,000-calorie diet.

Unsurprisingly medical experts do not recommend the Gorske diet. Tara Gidus, a registered dietitian in Florida, said Gorske probably has good genetics to thank for his health, alongside the fact that he resists the temptation to order fries and soft drinks with his burger.

She said she would be "less concerned about the bad stuff in the Big Mac and more concerned about the good stuff he's missing", such as fruit and vegetables.

Gorske said he likes other foods, including bratwurst and lobsters, but insists the Big Mac remains his true passion.

He said his wife jokes about ending his streak. "She says … when she has to put them in a blender, it's over," he said.

Before tucking into his 25,000th burger he added, somewhat needlessly: "I really do enjoy every Big Mac."

The Burger King

McFan Plan - Don Gorske by numbers

•Gorske has consumed 13,500,000 million in US Big Mac calories, compared to 12,250,000 if he'd eaten them all in a UK McDonalds, where the Big Mac comes in at 50 calories lighter.

•He has consumed 725,000 grams of fat, or the weight in grease of a large polar bear"

•At 1135 kilos of beef, Gorske has eaten the equivalent of two and a quarter cows, nose to tail.

•He's gulped down 400,000 Big Mac mouthfuls (by his own estimate of 16 bites per burger)

•It would have taken Sonya Thomas, the International Federation of Competitive Eating's record holder (Hamburger category), just three weeks to eat as many burgers.

• When he chomped into his first Big Mac in 1972, Americans spent around $3bn a year on fast food. Today that figure is more than $110bn.

•He would have to walk more than 90,000 miles to burn off all his Big Macs, the equivalent of more than 10 return trips from his Wisconsin home to the world's most remote McDonalds in Invercargill, New Zealand

•His thirty-nine year burger marathon has yielded him just 100 grams of iron – the same as found in 1000 olives.

•He's chewed through 6,250 grams of calcium, equivalent to that found in 521 teeth.

•His Big Mac intake averages out at 1.76 a day, every day for 14,235 days, meaning he would have hit the 12,848 mark around the time Pittsburgh was temporarily renamed Big Mac, USA for McDonalds' 25th in 1992.